The 6061 aluminum matrix composites reinforced with ZnO-coated Mg_2B_2O_5w were fabricated by squeeze casting method and followed by extruded under a technical equivalent condition. The mechanical properties and micro...The 6061 aluminum matrix composites reinforced with ZnO-coated Mg_2B_2O_5w were fabricated by squeeze casting method and followed by extruded under a technical equivalent condition. The mechanical properties and microstructures of the composites were investigated. The results showed that the elastic modulus of the as-cast composites increased straightly with increasing ZnO coating content. The ultimate tensile strength and yield strength of the as-cast composites rapidly increased initially and then declined with increasing ZnO coating content. However, the elongations of all the as-cast composites had similar values. The elongations of the composites were highly enhanced and the ultimate tensile strength of the composite without ZnO coating was the largest after extrusion. A number of whiskers in the composites with ZnO coating were fractured during the extrusion process, but the whiskers＇ breakage extent was limited with the increase of coating content.展开更多
TiB_2 ceramics powder was synthesized from B_2O_3-TiO_2-Mg system. The effects of TiB_2 addition as diluent on the combustion synthesis process were investigated. The results of thermodynamic calculation and experimen...TiB_2 ceramics powder was synthesized from B_2O_3-TiO_2-Mg system. The effects of TiB_2 addition as diluent on the combustion synthesis process were investigated. The results of thermodynamic calculation and experiments show that the increase of TiB_2 content ranging from 0 to 20wt% can reduce the adiabatic temperature T_(ad) from 3100 K to 2896 K and combustion temperature T_c from 2139 K to 1621 K respectively. The particle size and half width of the particle distribution are also increased with the addition of TiB_2 increasing from 0 to 20wt%. The combustion product is a mixture of TiB_2, MgO, and other intermediate phases. The leached product contains mainly TiB_2, TiO_2 and TiN, and its oxygen content is 7.77wt%.展开更多
In the paper we compare rutin with vitamin B2 in electrochemical investigation,electrochemcial parameters of adding DNA.It shows that both reduction and oxidation peak currents of rutin or vitamin B2 decrease with no ...In the paper we compare rutin with vitamin B2 in electrochemical investigation,electrochemcial parameters of adding DNA.It shows that both reduction and oxidation peak currents of rutin or vitamin B2 decrease with no change in the peak potentials,when DNA is added in rutin or vitamin B2 solution.An electrochemical inactive supramolecular complex DNA-Rt or DNA-VB2 was formed.The decrease in peak current was proportional to DNA concentration and can be used to determine DNA concentration.Change of peak current with the concentration of rutin or vitamin B2 is linear in sure range and can be used to determine rutin or vitamin B2concentration.A satisfactory result was obtained for the determination of rutin or vitamin B2 in tablet.展开更多
目的:探讨2型糖尿病患者血清血栓素B_2(TXB_2)水平变化及临床意义。方法:选择本院2014年7-12月收治的78例2型糖尿病患者作为病例组,并选择同时期本院门诊健康体检者80例作为对照组,采用放射免疫分析法测定两组对象血清TXB_2和内皮素(ET...目的:探讨2型糖尿病患者血清血栓素B_2(TXB_2)水平变化及临床意义。方法:选择本院2014年7-12月收治的78例2型糖尿病患者作为病例组,并选择同时期本院门诊健康体检者80例作为对照组,采用放射免疫分析法测定两组对象血清TXB_2和内皮素(ET)水平,通过Pearson相关分析法分析病例组TXB_2、ET与一般资料的相关性。结果:病例组血清TXB_2、ET水平均显著高于对照组,且病例组血清TXB_2、ET水平均随病程、Hb A1c、PBG、2 h PBG增加而升高,差异均有统计学意义(P<0.05);患者TXB_2、ET与病程、Hb A1c、PBG、2 h PBG均存在显著正相关性(P<0.05)。结论:2型糖尿病患者血清TXB_2、ET水平明显升高,应及时采取有效治疗措施将其血糖水平控制在正常范围内。展开更多
目的为加强我国检测机构对乳粉市场的监管,中国食品药品检定研究院(National Institute for Food and Drug Control,NIFDC)组织实施了乳粉中维生素B_1和B_2的含量测定的能力验证。方法制备了分割水平对的样品,采用单因素方差分析和t检...目的为加强我国检测机构对乳粉市场的监管,中国食品药品检定研究院(National Institute for Food and Drug Control,NIFDC)组织实施了乳粉中维生素B_1和B_2的含量测定的能力验证。方法制备了分割水平对的样品,采用单因素方差分析和t检验对样品均匀性和稳定性进行分析。对能力验证结果进行稳健统计分析,通过Z比分数评价实验室检测能力。结果样品通过均匀性和稳定性检验要求,满足能力验证计划要求。维生素B_1项目中,参加20个实验室验证,满意结果数为14,满意率为70.0%;维生素B_2项目中,参加22个实验室验证,满意结果数为15,满意率为77.2%;2项检测结果均满意的实验室有12个,满意率为60%。结论绝大多数实验室对乳粉中维生素B_1和B_2的测定处于良好水平,但未达到优良水平,仍需对检测方法进行统一认识,减少系统误差,加强各实验室内部的质量控制。展开更多
基金Project(2011CB612200)supported by the National Basic Research Program of China
文摘The 6061 aluminum matrix composites reinforced with ZnO-coated Mg_2B_2O_5w were fabricated by squeeze casting method and followed by extruded under a technical equivalent condition. The mechanical properties and microstructures of the composites were investigated. The results showed that the elastic modulus of the as-cast composites increased straightly with increasing ZnO coating content. The ultimate tensile strength and yield strength of the as-cast composites rapidly increased initially and then declined with increasing ZnO coating content. However, the elongations of all the as-cast composites had similar values. The elongations of the composites were highly enhanced and the ultimate tensile strength of the composite without ZnO coating was the largest after extrusion. A number of whiskers in the composites with ZnO coating were fractured during the extrusion process, but the whiskers＇ breakage extent was limited with the increase of coating content.
文摘TiB_2 ceramics powder was synthesized from B_2O_3-TiO_2-Mg system. The effects of TiB_2 addition as diluent on the combustion synthesis process were investigated. The results of thermodynamic calculation and experiments show that the increase of TiB_2 content ranging from 0 to 20wt% can reduce the adiabatic temperature T_(ad) from 3100 K to 2896 K and combustion temperature T_c from 2139 K to 1621 K respectively. The particle size and half width of the particle distribution are also increased with the addition of TiB_2 increasing from 0 to 20wt%. The combustion product is a mixture of TiB_2, MgO, and other intermediate phases. The leached product contains mainly TiB_2, TiO_2 and TiN, and its oxygen content is 7.77wt%.
文摘In the paper we compare rutin with vitamin B2 in electrochemical investigation,electrochemcial parameters of adding DNA.It shows that both reduction and oxidation peak currents of rutin or vitamin B2 decrease with no change in the peak potentials,when DNA is added in rutin or vitamin B2 solution.An electrochemical inactive supramolecular complex DNA-Rt or DNA-VB2 was formed.The decrease in peak current was proportional to DNA concentration and can be used to determine DNA concentration.Change of peak current with the concentration of rutin or vitamin B2 is linear in sure range and can be used to determine rutin or vitamin B2concentration.A satisfactory result was obtained for the determination of rutin or vitamin B2 in tablet.
文摘目的:探讨2型糖尿病患者血清血栓素B_2(TXB_2)水平变化及临床意义。方法:选择本院2014年7-12月收治的78例2型糖尿病患者作为病例组,并选择同时期本院门诊健康体检者80例作为对照组,采用放射免疫分析法测定两组对象血清TXB_2和内皮素(ET)水平,通过Pearson相关分析法分析病例组TXB_2、ET与一般资料的相关性。结果:病例组血清TXB_2、ET水平均显著高于对照组,且病例组血清TXB_2、ET水平均随病程、Hb A1c、PBG、2 h PBG增加而升高,差异均有统计学意义(P<0.05);患者TXB_2、ET与病程、Hb A1c、PBG、2 h PBG均存在显著正相关性(P<0.05)。结论:2型糖尿病患者血清TXB_2、ET水平明显升高,应及时采取有效治疗措施将其血糖水平控制在正常范围内。
文摘目的为加强我国检测机构对乳粉市场的监管,中国食品药品检定研究院(National Institute for Food and Drug Control,NIFDC)组织实施了乳粉中维生素B_1和B_2的含量测定的能力验证。方法制备了分割水平对的样品,采用单因素方差分析和t检验对样品均匀性和稳定性进行分析。对能力验证结果进行稳健统计分析,通过Z比分数评价实验室检测能力。结果样品通过均匀性和稳定性检验要求,满足能力验证计划要求。维生素B_1项目中,参加20个实验室验证,满意结果数为14,满意率为70.0%;维生素B_2项目中,参加22个实验室验证,满意结果数为15,满意率为77.2%;2项检测结果均满意的实验室有12个,满意率为60%。结论绝大多数实验室对乳粉中维生素B_1和B_2的测定处于良好水平,但未达到优良水平,仍需对检测方法进行统一认识,减少系统误差,加强各实验室内部的质量控制。
